Controller for electric motors.



No. 672,992. Patented Apr. 30, I901. E. .W. STULL.

CONTROLLER FOR ELECTRIC MOTORS.

(Application filed July 25, 1900.) [No Model.) 3 Sheets-Sheet l.

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No. 672,992. Patented Apr. 30, I90L E. W. STULL.

CONTROLLER FOR ELECTRIC MOTORS {Application filed July 25, 1900.\ (NoModel.) 3 SheetsSheet 3.

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W s A TTORNEY.

UNITED STATES PATENT OFFICE.

EMMETT W. STULIJ, OF .IOHNSTOI/VN, PENNSYLVANIA, ASSIGNOR TO THE LORAINSTEEL COMPANY, OF PENNSYLVANIA.

CONTROLLER FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters iatent No. 672,992, datedApril 30,1901.

Original application filed June 8, 1900, Serial No. 19,641. Divided andthis application filed July 25,1900. Serial No; 24,771. (No model.)

T0 at whom it may concern.

Be it known that I, EMMETT W. STULL, of .Iohnstown, in the county ofOambria and State of Pennsylvania, have invented a new and usefulImprovement in Controllers for Electric Motors, of which the followingis a full, clear, and exact description, reference being had to theaccompanying drawings, which form a part of this specification.

This invention has relation to apparatus for the control of electricmotors, and more particularly to apparatus for carrying into effect thenovel method of control described and claimed in my pending applicationfor patent, Serial No. 19,641, filed June 8, 1900, of which the presentapplication is a division. That method of control consists, broadly, instarting a plurality of motors (four or more) connected all in seriesand then changing them over to a relation in which they are all inparallel by certain intermediate steps in which the motors or motorelements are partly in series and partly in parallel, the control beingelfected mainly by utilizing the resist ance and counter electromotiveforce of the motors themselves, thereby dispensing to a great extent, ifnot altogether, with the use of wasteful external resistance.

The present invention consists, therefore, broadly considered, in amotor-controllerconsisting of a plurality of controlling elements orgroups of contacts, each of which is arranged to control one group ofmotors and is provided with contacts for connecting the motors of thatgroup both in series and in parallel and also the fields and armaturesalone in series and in parallel, means being also provided forconnecting said controlling elements themselves both in series and inparallel. These controlling elements also preferably have contacts soarranged as to make other minor circuit changes preparatory to theessential or running positions, whereby two abrupt changes in circuitconditions are avoided and the motor-circuit is not entirely broken atany time.

My invention also includes a reversing and cut-out switch for reversingthe motors and also for cutting out of circuit either group of motors atwill and having its contacts and connections so arranged as to obviatethe necessity of duplicating certain contacts of the controllingelements and enabling the contact arrangement and connections of saidelements to be materially simplified.

My invention also consists in the novel construction and combination ofparts, all as hereinafter described, and. pointed out in the appendedclaims.

In the further description of my invention reference will be had to theaccompanying drawings, forming a part of this specification.

In the drawings, Figure 1 is a planular de-- velopment or diagram ofcontrolling apparatus suitable for the practice of my invention. Figs. 2and 2 are views showing graphically the circuit conditions which areeffected in the several positions of the controller, Fig. 2 being acontinuation of Fig. 2; and Fig. 3 is a partial elevation of acontroller with the casing broken away.

In Fig. 1, to which reference will first be made in order to facilitatetracing the circuits at the different positions of the motors, I have inaddition to the full diagrammatic representation of the circuitsindicated graphically in dotted lines the connection of the severalmotor elements between the fixed contacts of the controller.

A A A A designate, respectively, the armatures of the four electricmotors No. 1, No. 2, No. 3, and No. 4:, and F F F F the fieldcoils ofthe same.

0' O designate the two main moving elements of the controller, and RSthe reversing and cut-out switch.

R designates artificial resistance for connection in circuit with themotors under certain conditions.

B O O is a blow-out coil.

G. wherever seen indicates a ground connection, and T indicates thetrolley or other connection to the high-pressure side of thesupply-circuit.

The members O O are preferably revolving drums of the well-known type,drum C having the contacts 1 to 39, inclusive, and drum C the contacts40 to 73, inclusive.

Z) 1) U, 850., to Z2 inclusive, designate the fixed contact-fingers,which cooperate with the contacts of the drum 0, and 5 to 5 inclusive,indicate the fingers, which cooperate with the contacts of drum C Thereversing-switch also has a plurality of contacts arranged in sixvertical lines corresponding to six different positions of the switch,indicated, respective1y,on the drawings Ahead, 3 and 4 ahead, 3 and 4back, Back, 1 and 2 back, and 1 and 2 ahead. Between the main-ahead andback positions is an open circuit or off position. The only contacts ofthis switch which it will be necessary to refer to in detail in tracingthe circuits hereinafter are those on the main-ahead position anddesignated ,2 z .2 &c., to 2' The fixed cooperating contact-fingers ofthis switch are designated 8 s 5 &c., to

The relative arrangement, grouping, and connections of the variousmovable contacts and the circuit connections of the several fixedcontacts will be best understood by reference to Fig. 1, on which theyare clearlyindicated, and detailed description thereof is thereforeunnecessary. Attention will, however, be called hereinafter to certainpeculiar features in the contact arrangement and the purpose thereofmade clear.

The two drums or cylinders O O are intergeared to revolve in unison bythe operation of a single handle H, as shown in Fig.

Assuming the fingers of the reversingswitch to stand on the line ofcontacts marked Ahead and the drums C C to have been moved to position1, the circuit is as follows: from trolley to blow-out coil B O O, tofinger b contacts 37 34, finger I), finger 3 contacts 5 .e", armature A,finger 3 contacts 2 z, finger s, finger 5 contacts 25 28, finger bfinger 5 contacts a 2 finger s armature A finger .9", contacts .2 z,finger s finger 1)", contacts 18 and 22, fingerlfi, field F, finger 1),contacts 9 and 12, finger b field F linger 5 contacts 3 and 2, finger b,finger 5", contact .2 finger finger b contacts 71 69, finger 5 finger 3,contacts 2 z, finger s, armature A finger 3, contacts .2 2 finger sfinger b contacts 63 64, ii nger Z2 finger-s contacts Z12 2 finger sarmature A finger 5 contacts Z13 .2 finger s finger 5 contacts 58 59,finger b field F finger 5 contacts 48 and 51, finger Z9 field F, finger8 contacts .2 5 finger to and through re sistance R to ground. The fourmotors are therefore all connected in series with each other and withresistance. Each drum 0 C it will be seen, controls through thereversing-switch the connections of two of the motors, and the two drumsare at this time connected in series through the said switch. Inposition 2 the only change made is due to the engagement of finger 5with grounded contact 40, which short-circuits a portion of theresistance R. In portion 3 the engagement of the finger b with thecontact 42 short-circuits the entire resistance and leaves the motors inplain series. In passing from position 3 to position 4. there are twomomenerases tary positions,indicated at 3 and 8 (See Fig. 2.) In theposition 3 the overlapping engagement of the finger b with the contact15 shortcircuits field F, and the finger b by overlapping contacts 51and 54 effects a similar short circuit of the field F In the position 3fingers b and b lose engagement, respectively, with the contacts 9 and4:8 and cut out the fields F F. In position No. 4 fingers and 5respectively, engage the contacts 6 and 45, thus reconnecting in thefields F F. These fields, however, are now respectively in parallel withthe fields F and F", since on each drum the current after passingthrough the arinatures will divide between the fingers b and b or thefingers b and I), the two branches after passing through the parallelfields reuniting in the upper group of contacts on each drum, as will bereadily seen from Fig. 1 without again tracing the circuit in detail. Atthe time this position is reached the motors will have developedsuflicient counter electromotive force to stand with safety theincreased current due to the paralleling of the fields, and acorresponding increase in speed will result. Between positions 4 and 5there are several intermediate positions which occur preparatory toconnecting the motors in multiple-series pairs. In position at theonlychange made is the breaking of the circuit through the field F byreason of the fact that the finger I) loses its engagement with thecontact 4-5. In position 4 this field is reconnected in circuit, but inseries, with the field F by reason of the fact that fingers b and b arelapping over into engagement with the contacts 49 and 52. Said field Fis, however, short-circuit-ed, as the finger Z) has not yet lost itsengagement with the contact 54:. In position 4 the (lisengagement offinger I) with the contact 5% removes this short circuit around thefield F", and at the same time the disengagement of the finger I) fromthe contact 42 and the engagement of the linger 5 with the contact 40put a portion of the resistance R back in circuit. In position at theengagement of the finger 5 (which has heretofore been idle) with thecontact 72 short-circuits the drum 0 and the two motors connectedthereto, and at position 4 which occurs momentarily thereafter, circuitis opened entirely on the drum C. It was in anticipation of this removalfrom circuit and the subsequent connection in parallel with the othertwo motors that a portion of the resistance was put back into circuit atthe position 4 since otherwise a too-sudden jump in speed might occur.Ido not, however, consider such use of resistance to be an absoluterequisite at this time. In position 5 motors 1 and 2 are again putincircuit by the engagement of the fingers b to Z) with the contacts onthe vertical line 5. The current after passing through the blow-out coilnow divides, one branch of the circuit being as follows: fii'iger 1),contacts 38 35, finger N, to and through armature A, back to finger bIIO to contacts 26 29, finger b armature A finger 12 contacts 19 and 23,finger b field F', finger 19 contacts 10 and 13, finger b field F finger6 contacts 4 and 1, finger b, to resistance R, through a portion of thelatter to finger h to contact 41, to ground. The other branch of thecircuit is to finger Z9 contacts 72 69, finger Z1 armature A finger bcontacts 63 64, finger Z7 armature A, finger Z9 contacts 58 59, finger bfield F finger Z9 contacts 49 52, finger b", field F and through aportion of resistance to ground by the same path as the first-describedbranch. It will of course be understood that a part of each branchcircuit is through the reversing and cut-out switch; but it was notthought necessary to again trace out in detail the connections throughthis switch. In position 6 the only change made is to remove thatportion of the resistance which was before in circuit, this beingeifected by the engagement of the finger b with the grounded contact 43.In position 6 fields F and F are respectively short-circuited by thefinger b lapping onto the contact 16 and the finger b" lapping onto thecontact 55. At position 6 the fields F F are removed from circuit by thebrushes b (J leaving the contacts 10 and 49, respectively. At position 7the engagement of the brushes b and b, respectively, with the contacts 7and 46 reconnects in the fields F F in multiple, respectively, with thefields 13 F At position 7 none of the fingers b to (J are in engagement,the circuit to the motors 3 and 4 being open. At position 7 motors 3 and4 are again connected in circuit, with their armatures in multiple andtheir fields in series. The multiple connection of the armatures iseffected by the fingers b b, and 17 engaging the contacts 70, 67, and65, return connections being to fingers b and 19 The two branches of thecircuit then unite and the current passes from contact 61 to finger b,to field F to finger Z9 to contacts 50 53, to finger 19 to field F toground through finger Z1 and grounded contact 44. At position 7 thecircuit is again opened on the drum 0 without disturbing the circuit ofmotors 3 and 4. At position 8 circuit is again closed on the drum 0, andthe motors 1 and 2 are again connected in parallel with the mo tors 3and 4, but with their armatures in parallel with each other and theirfields in series. The circuit through the motors 1 and 2 can be readilyfollowed in Fig. 1 without being traced in detail, the connectionscorresponding substantially with those just traced on the drum 0 Atposition 8' armatures A and A are cut out by reason of the fact that thefingers b and 19 lose engagement with the contacts 30 and 32 and thefingers h Z2 leave the contacts and 67. Position 8 leaves thesearmatures still cut out and also short-circuits their respective fieldsF and F by reason of the fact that the fingers b and b are lapping over,respectively, onto the contacts 8 and 47. At position 8 fingers b and blose engagement with the respective contacts 14 and 53, and thus out outthe said fields. At position 9, which is the final position, motors 2and 4 are reconnected in circuit entirely in multiple with each other,and the four motors are also in full multiple with each other. It willbe readily seen without tracing the circuits in detail that theengagement of the fingers b Z2 and b with the contacts 31, 33, and 36effects the multiple connection of armatures A and A while the similarengagement of the fingers b, I), and b with the contacts 66, 68, andefii'ects the multiple connection of the armatures A A; also, that theengagement of fingers b b b and b with the contacts 17, 20, 24, and 27effects the paralleling of the fields F F and the engagement of thefingers I), D b and Z2 with the contacts 56, 57, 61, and 62 elfect theparalleling of the fields F and F Inasmuch as in my method of controlthe motors are started all in series, it will be readily seen that theircombined ohmic resistance is sufficiently great to prevent a very largeinrush of current, so that comparatively little external resistance isrequired, or I may entirely omit the use of such resistance.

There is therefore comparatively little useless expenditure of current.At the same time I gain the advantage at starting of a maximum torque.After position 3 is reached the next notch or running position isposition 4, in which the paralleling of the fields elfects aconsiderable acceleration in speed. All the intermediate positionsbetween 4 and 5 are transitory positions, which are effected in rapidsuccession.

Positions 5 and 6 are running positions, and of course effect a furtherconsiderable acceleration in speed. The next running position isposition 7. Positions 7, 7 and 7 are transitory positions, as are alsopositions 8, 8 and 8 Positions 7 and 8, it will be seen, a'lford agradually-accelerating transition from position 6 to position 9, whichis that of maximum speed.

For want of space not all the transitory positions are indicated inFig 1. These positions, moreover, while they are well adapted to therunning positions to which they are preparatory, are not essential,since other preparatory circuit conditions might be employed.

By reference to the development of the reversing and cut-out switch, asshown in Fig. 1, it will be noted that when said switch is thrown toeither of the positions 1 and 2 back or 1 and 2 ahead the circuit willbe opened at fingers 8*, s s and s and also at fingers s s s s 8 so thatthe only contacts on the drum (3 which are in use at this position arethose in the upper or resistance group. Likewise when thereversing-switch is in either of the positions 3 and 4 back or 3 and 4ahead the circuit is broken at fingers s, 5, s s s 8, s .9 and s", sothat the only contacts of the drum 0 which are in use are those of thebottom group, which control the trolley connection to the drum 0 in itsseries positions. By this arrangement of the reversing and cut outswitch I am able to effect the various circuit combinations abovedescribed with one set of resistance-contacts, which are used with allthe motors, and also with either pair alone in circuit, and am alsoenabled to simplify the contacts for controlling the trolleyconnections.

I do not desire to limit myself to the exact construction andarrangement which I have herein shown and described, since it is obviousthat persons skilled in the art can readily change or modify the samewithout departing from the spirit and scope of my invention as it ispointed out in the appended claims.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. A controller for electric motors, having a plurality of maincontrolling elements arranged each to control one group of motors, meansfor connecting said elements either in series or in parallel with eachother, and contacts on each element for connecting the motors of itsgroup both in series and in parallel, and also for connecting certainelements of said motors in parallel with each other and in series withthe remaining elements.

2. A controller for electric motors, having groups of contacts, each ofwhich groups is arranged. to control one group of motors, and means forconnecting said group of contacts either in series or in parallel, thecontacts of each group being individually arranged in their group toconnect in different positions thereof respectively the motors of itsgroup all in series, all in parallel, with the fields in parallel witheach other and in series with the armature, and the armatures inparallel with each other and in series with the fields.

3. Acontroller for electric motors having a plurality of groups ofcontacts, a group of motors connected to certain contacts of each groupof contacts, means for varying the connection and relative engagement ofthe contacts of each group to connect the individual motors of thecorresponding group all in series, all in parallel, and also with eithertheir fields or their armatures only in parallel, and means for varyingat predetermined times the relative electrical connections of thecontact groups as'a whole.

4. A controller for electric motors, having a plurality of groups ofcontacts, a group of motors connected with certain contacts of eachgroup of contacts, and means for connecting the groups of contacts inseries and in parallel, the contacts of each group being arranged toconnect the motors of the corresponding group in series and also withtheir fields in parallel, and their armatures in se ries, while thegroups of contacts are seriesconnected, and to repeat the said circuitconditions andalso connect the armatures of each evaeoa motor group inparallel and their fields in series and also the motors as a Whole inparallel when the contact groups are connected in parallel.

5. A controller for electric motors, having a plurality of groups ofcontacts, a group of motors connected with certain contacts of eachgroup of contacts, and means for connecting the groups of contacts inseries and in parallel, the contacts of each group being arranged toconnect the motors of the corresponding group in series and also withtheir fields in parallel and their armatures in series while the groupsof contacts are seriesconnected, and to repeat the said circuitconditions and also connect the armatures of each motor group inparallel and their fields in series, and also their motors as a whole inparallel when the contact groups are connected in parallel, the parallelconnection of the armatures alone being effected in one group in advanceof a similar connection to the other group or groups.

6. A controller for electric motors, having a plurality ofgroups ofcooperative fixed and movable contacts and means for connecting saidgroups either in series or in parallel, a group of motors arranged to becontrolled by each group of contacts, said contacts having two separaterelative positions in which the motors of the corresponding groups areconnected in series, two separate positions in which the armatures areconnected in series and the fields in parallel, a fifth position inwhich the fields are connected in series, and a sixth position in whichthe motors of the group as a whole are connected in parallel, and meansfor shifting the connection of the groups of contacts themselves fromseries to parallel relation intermediate the first parallel connectionof the fields alone and the second series connection of the motors as awhole.

7. A controller for electric motors, having a plurality of groups ofcooperative fixed and movable contacts and means for connecting saidgroups either in series or in parallel, a group of motors arranged to becontrolled by each group of contacts, said contacts having two separaterelative positions in which the motors of the corresponding group areconnected in series, two separate positions in which the armatures areconnected in series and the fields in parallel, a fifth position inwhich the fields are connected in series, and a siXth position in whichthe motors of the group as a whole are connected in parallel, saidcontacts also having other intermediate positions in which the fields orthe armatures of its motor group or the group as a whole are temporarilyremoved from circuit, and means for shifting the connections of thecontact groups themselves from series to parallel relation intermediatethe first parallel connection of the fields alone and the second seriesconnection of the motors as a whole.

8. In a controller for electric motors, the

combination with two groups of electric motors, of two rotaryintergeared controllerdrums, each of which is provided with a group ofcontacts for controlling the motors of one motor group, said drums eachhaving two positions in which the contacts thereof connect the motors ofits corresponding group in series, two positions in which the fields ofsaid group are connected in parallel and the armatures in series, afifth position in which the armatures are connected in parallel and thefields in series, and a sixth position in which the motors of said groupare all connected in parallel, and means for connecting the said drumseither in series or in parallel, and for changing the connection fromseries to parallel intermediate the position of the first parallelconnection of the fields and the position of the second seriesconnection of the motors.

9. In a motor-controller, the combination with two controller-drums,each of which is provided with contacts and connections for controllingone pair of motors, of a reversingswitch arranged to reverse thedirection of the motors, and also to cut out either pair thereof withoutentirely cutting out of circuit the contacts of the correspondingcontroller-drum.

10. In a motor-controller, the combination with two controller-drumseach of which is provided with contacts and connections for theseries-parallel control of one pair of motors,external resistance fo 1'use with either one or both pairs of motors, a group of contacts on oneof said drums which determine the connection of said resistance, a groupof contacts on the other drum which controls the trolley connection tothe first-named drum in its series position, and an auxiliary switcharranged to reverse the motors and also to cut out of circuit eitherpair of motors and the series-paralleling contacts of the correspondingdrum, but having contacts for preserving the circuit connections of theresistancecontrolling contacts of one drum when the corresponding motorsare removed from circuit, and for preserving the circuit connections ofthe trolley-controllin g contacts of the other d rum when its motors areremoved from circuit.

In testimony whereof I have affixed my signature in presence of twowitnesses.

EMMETT W. STULL.

Witnesses:

BLANOHE M. SMITH, H. W. SMITH.

